Study provides a powerful weapon against schistosomiasis

View:192 Time:2017-02-16

Schistosomiasis is a detrimental disease caused by parasitic flatworms called schistosomes. It is one of the most common parasitic diseases in the world. According to the World Health Organization estimates, schistosomiasis afflicts up to 258 million people, especially in tropical and subtropical countries. Typical symptoms include fever, blood in stools or urine, and abdominal discomfort. There are already effective treatments for the devastating disease, such as praziquantel. But to date no vaccine is available. Reinfection is common in areas where the parasite occurs.

In a paper published in the journal PLOS Neglected Tropical Diseases, researchers from Oregon State University report that they identify a protein in intermediate snail hosts of schistosome parasites which may be a powerful weapon to control schistosomiasis. The study was carried out by a team headed by Michael Blouin.

Biomphalaria glabrata, an intermediate snail host for schistosomes, is a species of air-breathing freshwater snail. One possible way to reduce the incidence of schistosomiasis is by controlling the transmission of the parasite larvae from the infected snails. Snails have immune defenses against infections. Recent studies have revealed a genomic region in Caribbean Biomphalaria glabrata snails that has a great effect on their resistance to infection by schistosomes.

In the current study, Blouin and colleagues focused on one of the genes in this region, grctm6, which encodes the Guadeloupe Resistance Complex Transmembrane 6 (Grctm6) protein. By analyzing the expression of grctm6 in Biomphalaria glabrata snails and investigating the effect of Grctm6 deletion, they found that Grctm6 is expressed in snail hemolymph and is structurally similar to some other immune proteins. What’s more, inhibiting the protein in infected snails increased the number of Schistosoma mansoni cercariae released into the environment by the snails. The data suggest that grctm6 is a potential target for reducing transmission of schistosomes at the snail stage. The findings will have significant applications in the fight against the widespread and destructive disease.